Special Counsel Robert Mueller has referred cases on a group of prominent American lobbyists, including Democrat-connected superlobbyist Tony Podesta, to federal prosecutors in New York as part of an inquiry into whether the operatives worked as unregistered foreign agents.

Mueller also referred former Obama White House General Counsel Greg Craig and former Minnesota Republican Rep. Vin Weber to the New York office as part of the inquiry, according to CNN.

All three of the lobbyists worked with former Trump campaign chairman Paul Manafort on a campaign to help former Ukrainian President Viktor Yanukovych.

Mueller has indicted Manafort in two federal jurisdictions on a slew of charges related to his work for Yanukovcyh, including tax evasion and acting as an unregistered foreign agent. Manafort went on trial in Virginia on Tuesday.